Roberto Mancini tries to get his thoughts across to Yaya Touré during Manchester City's home defeat to United. Photograph: Andrew Yates/AFP/Getty Images

The mixed messages from Roberto Mancini began before the 164th Manchester derby and continued afterwards. They were compounded by some intriguing body language during Manchester City's 3-2 home defeat as debate swirled around the Italian's management style.

Before the game, Mancini said: "At the moment we have four strikers who can't score. Our season depends on our strikers." Clever psychology from a maverick among top managers? Or a clumsy carrot-and-stick approach that added to the sense of a manager out of tune with his players? By the close of the game, none of Sergio Agüero, Mario Balotelli (the starting forwards), or Carlos Tevez and Edin Dzeko (both second-half substitutes) had scored.

Mancini's man-management also meant public scorn for Samir Nasri for presenting "half" a barrier in the defensive wall that failed to defend Robin van Persie's winner, and led to the left-field selection of Balotelli ahead Tevez.

Mancini may wonder how City lost on Sunday to Manchester United at the Etihad after his side clawed back two first-half Wayne Rooney strikes to level with four minutes remaining. Beyond the fiercely loyal support, though, who waited 44 years for last season's title, Mancini's actions will provoke debate among the club's hierarchy. He is also confusing the wide pool of observers who have taken to Mancini's urbane manner and admire how he inspired a dressing room of big egos to come from eight points behind to claim last season's Premier League title.

On Sunday, Mancini took 51 minutes to agree with those who saw Balotelli's name in the XI for the season's most important match and wonder why it did not read Tevez. Balotelli, with only six previous league starts and one goal, was preferred to the Argentinian (12, and seven) and Dzeko (five, and six). Mancini's reasoning was the memory of Balotelli scoring twice and his pace causing Jonny Evans to be sent off in last season's 6-1 win at Old Trafford.

After handing him a gilded opportunity on the big stage, Mancini watched as Balotelli offered the kind of erratic display that continues to mark his career. There was the odd surge, odd clever touch or dribble. Yet his status as the next world-class star in waiting (Mancini's assertion) was undermined by the wrong choice of runs, errant passes and the familiar posture that suggests he does not care.

This had Mancini berating him throughout. Yet a damaging correlative of the manager's huffs at the footballer he "loves as a guy and a player" is how they hardly calmed the rest of the team, especially when many may wonder exactly why Mancini continues to persevere with the 22-year-old.

There is nothing new in a manager blowing his top in the technical area but the sight of Mancini turning away in disbelief at a player considered a gamble precisely because of the kind of display he was witnessing left him open to more accusations of foggy-thinking.

Van Persie's late winner ignited volcanic scenes. These included Tevez continuing a long running dispute with Ferguson by engaging in a touchline spat with United's manager. Tevez's ill-feeling is fuelled in part by his dismay at Ferguson preferring Dimitar Berbatov when the Argentinian was at United. So a follow-up question consisted of how hard it was to leave out Tevez, especially given his appetite to show Ferguson his error. "After the game, it is easy to say this. It is not easy [before], when you have four strikers like we have," Mancini said.

Balotelli's misfiring performance did not see Tevez introduced until five minutes into the second half, which provoked the question of why wait until then? "In the first-half, we had to sub Vinny [Kompany] and I wanted to wait to see if Mario could play well," Mancini said. "After five minutes, I saw he played like he played in the first half and I didn't want this." If he hoped to save a substitution for a more crucial stage of the contest the logic of allowing Balotelli only five more minutes to show he could improve enough to do so may again baffle some.

Van Persie's free-kick beat Joe Hart via a deflection from Nasri's ankle after he turned his body sideways. Before this, Tevez, the fourth man in the wall, had wandered away. Mancini said: "I called Carlos to return to the wall but I was too far away on the bench." On Nasri, he was more damning: "We had two and a half players there, we didn't cover very well."

Nasri's action suggests a lack of will for the collective cause, Tevez's a breakdown in communication – also a pointer to a lack of team cohesion. Mancini's refusal to protect either with a bland soundbite compounds the sense of a manager hardly in concert with his squad. Ferguson's mantra at United is that anything potentially divisive stays in-house.

Next up for City is Saturday's tricky trip to Newcastle United. A defeat would be the third on the bounce, and would leave Mancini appearing as a man marooned by results.